Artifactual Displacement of Ductal Carcinoma In Situ (ADDCIS) (Toothpaste Effect): A Mimicker of Invasive Ductal Carcinoma

In conclusion, ADDCIS mimics IDC, particularly given its permeative pattern and absence of myoepithelial cells. ADDCIS is most common in lumpectomies but can occur in mastectomies or core biopsies. Diagnostic clues include smudged nuclear chromatin, lack of stromal response, and linear pattern of displacement in larger lesions. The benign follow-up without systemic therapy supports our view that ADDCIS does not represent true IDC.
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research